Duo tracks are allowed; but each map counts as one track for each author involved.

MTC should be present in the track name. Example: Simpli-city (MTC); or [mtc] Ruins of Life;
or MTC - time for dreams (check that any special characters do not break in the TM or MX track name).

The track should be built in the most recent version of the game.

Tips

If judges can drive a time considerably under 4 minutes, they may choose to deduct theme points. If you're a slower driver you may want to pad your track with extra length. Ask someone faster to beta test your track if you're not sure.

Make it possible to continue by respawning from any CP.

Give clear indication where the route leads. In an endurance track it's sometimes possible to jump to another section of the route and miss CPs. Block off wrong routes and make the correct route the obvious one.

Be careful of introducing cuts. The longer your track, the more likely cuts may be introduced. Adding plenty of strategically placed CPs helps prevent this.

Deadlines

Your track should be uploaded before the end of Sunday January 21, 2018 at midnight EST

Public voting will go from January 22nd to February 5th

Results are calculated the week of February 5th

Prizes Honour and the right to brag! (Jozii used to say that. I hope some still remember him? )
The top 3 winners will receive a showcase of a track of their choice (< 10 awards)

Multilap implies there being multiple laps, and last I checked "one " doesn't suggest that so I'd assume you're fine. Even then, you could always put an end piece/item near the start piece if it isn't allowed.

Stadium alone does not work for envimix, but you can always build your map in the standard Stadium titlepack; you need all 4 environments if you want to do any envimixing. It does not matter if you are using the Steam version or standalone of ManiaPlanet for this, either.

Titlepacks always go in documents->ManiaPlanet->Packs, except for the default titlepacks (Stadium, Canyon, etc) which will just be available to owners of the environments. Packs will also always end in .gbx, so if you have a .zip or other compressed folder you'll need to extract the files with 7-zip or another similar tool.